1. Field of the Invention
The present invention relates generally to comparing sets of complex data, and in particular to a system for making integrated, visual comparisons between characteristics of complex entities represented by data subsets.
An example within this general field and one to which the present invention is particularly applicable, is surgical transplantation. This includes prosthetic implants, reimplantation of expanded autograft tissues and most particularly and valuably, to human allograft transplantation into humans.
Though not limited to this field, the invention provides, in this context, a novel, structurally based, practical system for matching potential recipient parameters to a donor organ or prosthesis and means for controlling and communicating inventory data on donor organs and prostheses. This enables a provider of prostheses or organs to provide significant assistance to the surgical and scientific team in the selection and decision making process. The invention is further concerned with the field of means for enhancing the quality of clinical judgment brought to bear on individual transplant and implant cases by virtue of the manner and form in which the information is presented. The present invention has significant utility for any group of suppliers and users which face similarly complex sets of data parameters.
2. Description of Related Art
For the lay person and indeed, the scientific and medical communities, matching a requirement to an available product or service may be adequately addressed via the well-known device of a catalog of inventory. Typically, this will involve a general specification of the item, with or without an illustration and followed by a simple numerical or alphanumerical code, which enables an appropriate selection to be made. Such simple systems work well for the vast majority of items which society needs to transfer between suppliers and users because users can typically determine whether a particular item meets their needs by reviewing the general specification of the item and the illustration, if provided, in the catalog. If users are still unsure as to the adequacy of a particular item for their needs, there are generally personnel available to answer questions.
In cases of custom requirements, the additional use of mechanical or electrical drawings, bills of materials, specifications and other forms of extended data, are tools that are well known and understood. In most situations they serve the parties adequately.
All of these listing tools typically need to be used in sequence or side-by-side in a disparate and non-integrated manner. There is no system known to the present inventors which unifies all important data subsets relating to very complex products and which allows simultaneous quantitative and qualitative judgments to be derived from it.
In the rapidly developing field of organ transplantation and to a lesser extent in the field of prosthetic implantation, however, there are many more points of difference in the relationship between the supplying entity and the potential recipient than are encountered in the supplier-vendor relationships of normal commerce. These differences, the complexity and number of matching parameters and the life-critical nature of the transaction, render simple inventory systems at best, inadequate, and at worst, unworkable. In the absence of advances in the state of the art, this problem will worsen as xenotransplantation becomes accepted and commonplace.
With organ transplantation, in particular, most requirements relate to situations where the potential recipient has a relatively short or very short time in which to receive a replacement, if he or she is to survive. This is because failure of a major organ is usually accompanied by deterioration of other systems, leading to a generalized metabolic catastrophe. An article in FORTUNE magazine published Nov. 25, 1996, stated that "About 18,000 human organs are transplanted annually in the U.S., while an estimated 100,000 Americans die waiting for a spare heart, liver, kidney, or other organ." The serious shortfall in supply is one of the significant driving forces behind the major upsurge in interest in xenotransplantation and in particular, projects which are currently being undertaken by a number of companies to develop genetically modified pigs as a potential future source of organs. For the first time, the possibility arises of generating an adequate number of organs with physical characteristics which may be matched better than is often the case with human allografts, where the emphasis has necessarily been on matching by tissue-typing alone.
This increases the need for inventory systems which will be able to deal with many additional important parameters. However, even the currently used tissue histocompatibility parameters are presented as line-by-line data, which encourages item-by-item comparisons and value judgments which are, of necessity, fragmented. These inventors are not aware of any transplant team nor donor organ supplying organization which uses or has proposed using, any system which offers a basis for integrating transplant parameters into a visual presentation which would facilitate an integrated decision making process.
Orthopedic surgeons are one group of medical specialists who carry out large numbers of implantation procedures. They have complex needs in respect of such procedures but they have also been better provided for than most groups of specialists with means for making assisted judgments. For instance, radiography of the calcified skeleton has allowed accurate measurements to be made on bones and joint spaces for many decades. Additionally, in the example of total hip-joint replacement, line-art transparent overlays of a series of standard sizes of a preferred prosthesis may be placed over appropriate x-ray views of the subject joint and adjacent bones until the right size is identified. By these means, a surgeon is able to predict, within reasonable limits, what will be needed, from inventory, at the time of surgery and normally will be able to comfortably predict the outcome.
Even though the range of metal and plastic conventional prosthetic implants now in common use is very wide, such implants do not, even at their most complicated, ever approach the complexity of a human or animal organ. The prediction of intra-operative requirements and outcomes in prosthetic replacements of soft tissues has been considerably assisted by the advent of techniques such a magnetic resonance imaging (MRI) and computerized axial tomography scanning (CAT), though these techniques are complex and relatively costly. However, the only so-called advance in the selection, supply and inventory process, for any type of conventual prosthesis has been the advent of Electronic Data Transfer (EDT). In such systems, manufacturers provide on-line, line-by-line inventory data to their purchasing client groups who may place orders for their requirements within the system. In fact, this is just an on-line catalog listing and order processing facility and is not well-suited to highly complex, urgent situations.
Meanwhile, tissue regeneration techniques are improving rapidly. For instance, human tissues can now be removed from a subject and grown outside the body for reimplantation later. Techniques are being developed which will use both organic and inorganic materials, as scaffolds, to support the growth of such explanted tissues. These scaffold materials will have varying antigenic potential and it is known, in addition, that processing human tissue, extracorporeally, can lead to an antigenic profile which may diverge from that of the original sample. As reimplantation of expanded autogenous tissues, with or without scaffolds, gains acceptance, the old and accepted definitions of prosthetic replacement are becoming less adequate.
Sophisticated surgical opportunities, with tissue-augmented prostheses, will increase demands on surgical teams, who will require better tools and more varied data to prospectively evaluate the chances of a successful outcome. New means for matching the complex needs of the user to the supplier are urgently required.
This dilemma may be illustrated by considering the well documented phenomena of hyperacute, acute and long term rejection. While it is likely that progress will be made in these areas, it is inevitable that this progress will be accompanied by a proliferation of data species which will need to be collected and considered. This need will apply not only to potential recipients but will also need to be `attached`, maintained and supplied in respect of replacement organs and tissue augmented prostheses.
Transplant teams comprise individuals, from varying technical fields, who have great experience, as well as practical and technical skills. They also have human quality of judgment, the subtlety of which is refined by repeated exposure to demanding situations. There is and will be an increasing need for improved data presentation which will allow that subtlety of judgment to be exercised, enhanced and refined.